Vibratory compactors have parts that are caused to vibrate due to the rotation of a shaft that incorporates an eccentric weight. It is desirable to properly isolate the vibration from the rest of the structure for such compactors. For example, the vibration isolation method used for the drums of vibratory compactors for soil and asphalt is schematically shown in FIG. 1.
Vibration isolation is usually required between the drum and the rest of the machine, i.e., a frame as shown in FIG. 1.
Vibration isolation is typically achieved by using a resilient material, like rubber or metallic spring which is configured to connect the vibrating part to the rest of the machine. The use of rubber isolators between ‘the drum and a carrier bearing’ and ‘the drum and a drive plate’ is shown in FIG. 1.
A more sophisticated method of vibration isolation utilizes a secondary mass, which is usually referred to as “dual stage isolation”. If the mass and isolators are chosen correctly, this dual stage isolation system can result in better isolation than the “single stage isolation” system shown previously. The aim of the dual stage isolation system is to allow the dual stage isolation mass to have a lower amplitude vibration than the drum, thus transmitting less vibration to the frame.
The concept of this dual stage isolation system has been used in the past on an Ingersoll-Rand asphalt compactor. The dual stage isolation system is shown schematically in FIG. 2. There is a dual stage isolation mass between “the drum and the carrier bearing” and between “the drum and the drive plate”, and each of the components is buffered with an isolator.